Polyaspartate is a biopolymer synthesised from L-aspartic acid, a natural amino acid. Typically aspartic acid is heated to produce a polysuccinimide. The polysuccinimide is subsequently ring opened to form the polyaspartate material. Polyaspartate materials have been used in many different areas. An overview of the various uses is stated in U.S. Pat. No. 6,495,658. These range from biological coatings and anti-scalants to dispersants in detergents. One attraction of such biopolymers is that they are biodegradable, which is becoming an increasingly important issue in relation to the environment.
U.S. Pat. No. 6,495,658 B2 discloses the thermal polymerisation of monomers of aspartic acid with a comonomer, such as monosodium aspartate to produce copolymers which comprise aspartate units and succinimide units.
U.S. Pat. No. 6,903,181 B2 discloses methods of synthesis of polysuccinimide. Also disclosed are methods of forming derivatives by a ring-opening reaction.
WO 03/014193 A1 discloses polyaspartate derivatives for use in detergent compositions. It is alleged therein that the disclosed polyaspartate derivatives provide improved fabric whiteness appearance and/or improved soil-release of stains from fabric and/or better dispersancy of particulate soils. Exemplified therein are polyaspartate derivatives that are derivatised with both hydrophilic and hydrophobic groups, some of which contain residual polysuccinimide groups.
There still remains a need for laundry compositions comprising one or more components with good biodegradability and which still provide good performance towards removal of particulate soils and oily stains.
Accordingly it is an object of the invention to provide a laundry composition that fulfils one or more of the aforementioned needs.